In the commercial air transport industry, it is desirable to design aircraft configurations that yield reduced fuel burn per seat-mile, as fuel burn per seat-mile is a measure of fuel efficiency. Efficient aircraft configurations are ever more important as fuel costs continue to increase. Aircraft aerodynamic drag and fuel burn are generally reduced as the aspect ratio of the aircraft wing increases. Similarly, operating larger aircraft which carry more passengers and payload is generally more efficient between two destinations than flying several trips with smaller aircraft. Thus, larger aircraft and aircraft with longer wingspans tend to be more efficient. However, taxiway spacing and gate locations for most airports were designed for aircraft with smaller wingspans than many aircraft that may be produced with today's technology.